Wireless IC device

Abstract

A wireless IC device that is operable in a wide band and is suitable for RFID systems includes a radiating plate and an electromagnetically coupled module constituted by a wireless IC that processes transmitted/received signals and a feeding circuit board having a feeding circuit and coupled with the wireless IC. The radiating plate includes a linear electrode bent at a bent portion and apparently sectioned into two linear electrode portions having different lengths. The electromagnetically coupled module is arranged such that the feeding circuit board and the linear electrode portions are electromagnetically coupled. The wireless IC is operated by signals received by the radiating plate, and response signals from the wireless IC are radiated outward from the radiating plate.

1. A wireless IC device comprising:
 a wireless IC arranged to process transmitted/received signals; 
 a feeder circuit connected to the wireless IC and including an inductance element; 
 a radiating plate coupled to the feeder circuit; wherein 
 the radiating plate includes a linear electrode that is bent at a predetermined position so as to be sectioned into two linear electrode portions; 
 the two linear electrode portions have different resonant frequencies, and at least one portion of each of the two linear electrode portions extend side by side with one another; and 
 the inductance element and each of the two linear electrode portions of the radiating plate are electromagnetically coupled to one another. 
 
     
     
       2. The wireless IC device according to  claim 1 , further comprising a feeder circuit board including the feeder circuit, wherein the feeding circuit board includes a multilayer substrate. 
     
     
       3. The wireless IC device according to  claim 1 , wherein the radiating plate is provided on a flexible substrate.